How To: Identify Common Causes of Conveyor Belt Misalignment

A belt conveyor which is properly designed, constructed, erected and maintained theoretically will consistently run true without concern for belt misalignment.  However, properly aligned belts are normally the exception rather than the rule.

K-Commander® Self Centring Idler

The following conveyor belt troubleshooting checklist is provided to assist you in the your efforts to correct belt misalignment problems that invariably lead to premature failure of belting, idlers and pulleys.

  1. Sunken or not level foundations.
  2. The driving and idler pulleys not normal to the conveyor centerline and not parallel with each other.
  3. Conveyor rollers of various diameters installed; or seized or out of round rollers.
  4. Transverse forces applied to the belt by items such as over tight angled belt scrapers.
  5. Material build up on the pulleys, belt or rollers.
  6. Damaged, twisted or missing conveyor idler frames.
  7. Crosswinds
  8. Uneven placement of load on the belt or the belt being loaded off centre.
  9. Incorrect belt storage which has caused the belt to wrap or bow.
  10. Belting of a different manufacture in the same length.
  11. Poor workmanship with belt splicing/slitting/ends squaring.  This includes localised edge repairs with associated tension differences.
  12. Transition idlers not installed or unevenly adjusted.
  13. Poor quality pulley manufacture with the diameter ot symmetrical to the centreline of the belt. (Pulley faces may be worn)
  14. Excessive tensioning of the belt preventing all of the idlers from helping to direct the belt.
  15. Under tensioning of the belt which restricts the pulleys from controlling the belt.  This also applies to all pulleys including take-ups.
  16. Uneven or misaligned pulley take-up carriage forces.
  17. Uneven skirting pressure.
  18. Worn pulley faces, pulley lagging unevenly worn or pulley shaft locking elements worn.
  19. Trough and return idlers not installed at right angles to the axial centreline and therefore the belt not making proper contact with the rollers.
  20. Trough idlers installed back the front with the lead roller not leading.
  21. Offset trough idlers being used on reversing conveyors rather than in-line idlers being used.
  22. Out of round or seized rollers giving the belt contact forces asymmetric to the centreline.
  23. Poor belt quality with the weave/fabric asymmetric to the centreline.
  24. The belt hotter on one side than the other, for example near a furnace; or one side of the belt running wet.
  25. Travelling trippers and shuttle not running.
  26. Mechanical fasteners not installed square.
  27. Extraneous articles fouling the conveyor belt.
  28. The belt too stiff for the idler width or trough angle, therefore not allowing the idlers to direct the belt.
  29. Return idler spacing too great to direct the belt.
  30. Existing self-aligning idlers worn out, seized, or locked into position; installed incorrectly or in wrong location.